Drop Latex test cases.

Texlive does not xpatch extensions and therefore some test cases fail:

~~~
  1) Failure:
TestFiles#test_/builddir/build/BUILD/kramdown-2_3_1/usr/share/gems/gems/kramdown-2_3_1/test/testcases/span/04_footnote/backlink_inline_text_to_latex_compilation [/builddir/build/BUILD/kramdown-2.3.1/usr/share/gems/gems/kramdown-2.3.1/test/test_files.rb:153]:
 LaTeX Error: File `xpatch.sty' not found.
 Paragraph ended before \deferred@thm@head was complete.
<to be read again>
 LaTeX Error: Missing \begin{document}.
 LaTeX Error: \begin{document} ended by \end{quotation}.
 Paragraph ended before \@xverbatim was complete.
<to be read again>
~~~

Let Texlive maintainer to decide the essential components. The Latex
functionality is not crucial from Kramdown.

Resolves: rhbz#1951246

rubygem-kramdown.spec

@@ -3,7 +3,7 @@
 
 Name: rubygem-%{gem_name}
 Version: 2.3.1
-Release: 2%{?dist}
+Release: 3%{?dist}
 Summary: Fast, pure-Ruby Markdown-superset converter
 
 License:	MIT
@@ -19,14 +19,6 @@ BuildRequires:	rubygem(stringex)
 # Recommends:	rubygem(stringex)
 # Some additional dependency for check
 BuildRequires:	tidy
-BuildRequires:	tex
-BuildRequires:	tex(acronym.sty)
-BuildRequires:	tex(amssymb.sty)
-BuildRequires:	tex(amsmath.sty)
-BuildRequires:	tex(amsthm.sty)
-BuildRequires:	tex(amsfonts.sty)
-BuildRequires:	tex(utf8x.def)
-BuildRequires:	tex-ec
 Requires:	ruby(release)
 Requires:	ruby(rubygems)
 BuildArch: noarch
@@ -106,6 +98,10 @@ popd
 %doc	%{gem_docdir}
 
 %changelog
+* Thu May 13 2021 Vít Ondruch <vondruch@redhat.com> - 2.3.1-3
+- Drop Latex test cases.
+  Resolves: rhbz#1951246
+
 * Fri Apr 16 2021 Mohan Boddu <mboddu@redhat.com> - 2.3.1-2
 - Rebuilt for RHEL 9 BETA on Apr 15th 2021. Related: rhbz#1947937